diff --git a/Makefile b/Makefile
index e93ea5f..236dbb8 100644
--- a/Makefile
+++ b/Makefile
@@ -42,3 +42,6 @@ local-debug:
 
 local-down:
 	bash deploy/local/scripts/down-local.sh
+
+validate-prophet-mesh-scope-mirror:
+	node scripts/validate-prophet-mesh-scope-mirror.mjs
diff --git a/contracts/prophet-mesh/prophet-mesh-memory-scope.v0.1.json b/contracts/prophet-mesh/prophet-mesh-memory-scope.v0.1.json
new file mode 100644
index 0000000..4db6d63
--- /dev/null
+++ b/contracts/prophet-mesh/prophet-mesh-memory-scope.v0.1.json
@@ -0,0 +1,65 @@
+{
+  "schemaVersion": "memory-mesh.cross-repo-scope-mirror.v0.1",
+  "kind": "CrossRepoScopeMirror",
+  "contractVersion": "v0.1",
+  "mirrorId": "memory-mesh:prophet-mesh-memory-scope:v0.1",
+  "createdAt": "2026-06-10T00:00:00Z",
+  "sourceAuthority": {
+    "repo": "SocioProphet/prophet-mesh",
+    "path": "specs/runtime-release-bundle.yaml",
+    "contractVersion": "v0.1",
+    "claim": "memory_scope field in execution_trace must be explicit and non-empty"
+  },
+  "mirrorAuthority": {
+    "repo": "SocioProphet/memory-mesh",
+    "path": "contracts/prophet-mesh/prophet-mesh-memory-scope.v0.1.json",
+    "attestation": "memory-mesh independently mirrors the memory-scope policy boundary established by prophet-mesh"
+  },
+  "scopePolicy": {
+    "requiredField": "execution_trace.memory_scope",
+    "allowedScopePatterns": [
+      "relationship_context:approved",
+      "noetica-session-local",
+      "noetica-session-local:*",
+      "unscoped"
+    ],
+    "prohibitedValues": [null, ""],
+    "enforcement": "reject_if_absent_or_empty",
+    "effectBoundary": {
+      "workspaceWriteEnabled": false,
+      "externalSendEnabled": false,
+      "effectEnabled": false
+    }
+  },
+  "privatePreviewInvariants": [
+    "execution_trace_must_include_memory_scope",
+    "memory_scope_must_be_explicit",
+    "memory_scope_must_not_be_empty_string",
+    "memory_scope_must_match_allowed_pattern_or_be_scoped_local"
+  ],
+  "nonProductionBoundary": {
+    "claim": "This mirror contract covers dry-run and receipt-only modes only. Live execution scope policy requires a separate contract version.",
+    "coveredModes": ["dry_run_receipt_preview", "receipt_only"],
+    "excludedModes": ["live_execution"]
+  },
+  "crossRepoTraceability": {
+    "prophetMeshAdapterRef": {
+      "repo": "SocioProphet/agentplane",
+      "path": "contracts/prophet-mesh/prophet-mesh-agentplane-adapter.v0.1.json",
+      "contractVersion": "v0.1",
+      "mergeCommit": "faa767f42028ad0f2475c993700cdbef8490a38e",
+      "contentSha256": "38a3edb62813521a62f257f3f952271255d25dc3a05a14d6b96f04a6ff9b4268",
+      "mode": "dry_run_receipt_preview"
+    },
+    "runtimeReleaseBundleContract": {
+      "repo": "SocioProphet/prophet-mesh",
+      "path": "specs/runtime-release-bundle.yaml",
+      "invariant": "execution_trace_must_include_memory_scope"
+    }
+  },
+  "promotionNotes": [
+    "Memory-scope authority was self-attested in prophet-mesh only prior to this mirror.",
+    "This contract closes the symmetry gap: registry mirrors choir authority, model-router mirrors routing policy, agentplane projects execution receipts, memory-mesh now mirrors memory-scope policy.",
+    "No live execution scope is claimed. Non-production boundary applies."
+  ]
+}
diff --git a/scripts/validate-prophet-mesh-scope-mirror.mjs b/scripts/validate-prophet-mesh-scope-mirror.mjs
new file mode 100644
index 0000000..815a819
--- /dev/null
+++ b/scripts/validate-prophet-mesh-scope-mirror.mjs
@@ -0,0 +1,81 @@
+#!/usr/bin/env node
+/**
+ * Validate the prophet-mesh memory-scope mirror contract.
+ * Lane G — confirms the mirror is structurally sound and cross-repo refs are present.
+ */
+import { readFile } from 'fs/promises'
+import { fileURLToPath } from 'url'
+
+const CONTRACT_PATH = 'contracts/prophet-mesh/prophet-mesh-memory-scope.v0.1.json'
+const REQUIRED_FIELDS = [
+  'schemaVersion', 'kind', 'contractVersion', 'mirrorId',
+  'sourceAuthority', 'mirrorAuthority', 'scopePolicy',
+  'privatePreviewInvariants', 'nonProductionBoundary', 'crossRepoTraceability'
+]
+const REQUIRED_INVARIANTS = [
+  'execution_trace_must_include_memory_scope',
+  'memory_scope_must_be_explicit',
+  'memory_scope_must_not_be_empty_string'
+]
+const REQUIRED_MODES = ['dry_run_receipt_preview', 'receipt_only']
+
+function assert(condition, message) {
+  if (!condition) throw new Error(message)
+}
+
+async function main() {
+  const raw = await readFile(CONTRACT_PATH, 'utf8')
+  const contract = JSON.parse(raw)
+
+  for (const field of REQUIRED_FIELDS) {
+    assert(field in contract, `missing required field: ${field}`)
+  }
+
+  assert(contract.kind === 'CrossRepoScopeMirror', 'kind must be CrossRepoScopeMirror')
+  assert(contract.contractVersion === 'v0.1', 'contractVersion must be v0.1')
+
+  const policy = contract.scopePolicy
+  assert(policy.requiredField === 'execution_trace.memory_scope', 'scopePolicy.requiredField must be execution_trace.memory_scope')
+  assert(policy.enforcement === 'reject_if_absent_or_empty', 'scopePolicy.enforcement must be reject_if_absent_or_empty')
+  assert(policy.effectBoundary.effectEnabled === false, 'effectBoundary.effectEnabled must be false')
+  assert(policy.effectBoundary.workspaceWriteEnabled === false, 'effectBoundary.workspaceWriteEnabled must be false')
+
+  for (const invariant of REQUIRED_INVARIANTS) {
+    assert(
+      contract.privatePreviewInvariants.includes(invariant),
+      `missing required invariant: ${invariant}`
+    )
+  }
+
+  const boundary = contract.nonProductionBoundary
+  for (const mode of REQUIRED_MODES) {
+    assert(boundary.coveredModes.includes(mode), `nonProductionBoundary.coveredModes must include ${mode}`)
+  }
+  assert(!boundary.coveredModes.includes('live_execution'), 'live_execution must not be in coveredModes')
+
+  const trace = contract.crossRepoTraceability
+  assert(typeof trace.prophetMeshAdapterRef === 'object', 'crossRepoTraceability.prophetMeshAdapterRef required')
+  const ref = trace.prophetMeshAdapterRef
+  assert(ref.repo === 'SocioProphet/agentplane', 'adapter ref repo must be SocioProphet/agentplane')
+  assert(typeof ref.contentSha256 === 'string' && ref.contentSha256.length === 64, 'contentSha256 must be 64-char hex')
+  assert(ref.mode === 'dry_run_receipt_preview', 'adapter ref mode must be dry_run_receipt_preview')
+
+  console.log(JSON.stringify({
+    ok: true,
+    contractPath: CONTRACT_PATH,
+    mirrorId: contract.mirrorId,
+    scopePolicy: contract.scopePolicy.enforcement,
+    invariantsVerified: REQUIRED_INVARIANTS.length,
+    adapterRefSha256: ref.contentSha256.slice(0, 16) + '...',
+    nonProductionBoundary: boundary.coveredModes
+  }, null, 2))
+}
+
+main().catch((error) => {
+  console.error(error instanceof Error ? error.message : String(error))
+  process.exit(1)
+})
+
+if (process.argv[1] === fileURLToPath(import.meta.url)) {
+  // already runs via top-level await equivalent above
+}